Ascarina J.R.Forst. & G.Forst.

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

A genus of 12 species, with one species in Madagascar and the remaining taxa from Borneo through Malesia to the Pacific and New Zealand; four species are in New Guinea.

Morphology General

Latex or sap absent (not recorded)

Morphology General Habit

Glabrous Plants dioecious or monoecious Shrubs or small to large trees to 25 m; aromatic; branches jointed at the nodes and the bases of the internodes sometimes swollen

Morphology Leaves Stipules

Stipules very small, subulate

Morphology Leaves

Leaves simple, decussate, often with intermediate leafless nodes, leaves coriaceous, obtusely serrate, the serrations often gland-tipped; petiole short

Morphology Reproductive morphology Inflorescences

Inflorescences terminal or in the upper axils, compound spikes with flowers grouped in sessile cymes with an abaxial male flower and 1 or 2 adaxial female flowers essentially representing a bisexual flower

Morphology Reproductive morphology Flowers

Flowers much reduced, without conspicuous perianth. Staminate flowers: reduced to 1–2 subsessile anthers with parallel linear locelli opening lengthwise (in New Guinea)

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistillate flowers: ovary superior, ovoid-globose, sessile, 1-locular, ovule 1, pendulous; stigma sessile, truncate or 2-lipped

Morphology Reproductive morphology Fruits

Fruit a fleshy drupe, relatively small, purple-grey turning black when mature, obovoid, with thin, succulent exocarp and stony, smooth or verrucose, unspecialised endocarp

Morphology Reproductive morphology Seeds

Seeds ovoid, flattened, with smooth testa, aril lacking.

Ecology

Ascarina in New Guinea are medium to large trees in primary rain forest, especially montane forests, but they have also been collected from open habitats; from 450 to 3300 m elevation. The genus can be easily recognised vegetatively by the conspicuously jointed nodes with the internodes often swollen at the base, and the decussate leaves with serrate leaf margins often with leafless internodes. The plants have an aromatic smell reminiscent of Piperaceae when crushed, and when fertile, spicate terminal inflorescences with reduced, unisexual flowers with no conspicuous perianth, and the fruits turning black when mature.